In many electrical utilities, in order to prevent the effects of the electrostatics or the other abnormal electrical ions, it is necessary to add grounding wires for the purpose of discharging. For ordinary audio apparatus, apparently, this kind of grounding structure is more important. However, in most of the audio apparatus, designs related to their ear phone sockets (1) are shown in FIG. 1, which only have the conventional basic functions, and do not have the related arrangements of grounding structures, thus lead to the shortcomings for usage.